In recent years, a new content-presenting method of presenting a haptic feedback depending on an image and sound attracts interest. For example, in such a method, each of users has a haptic-feedback presenting device, and a control apparatus that reproduces an image or the like instructs each of the haptic-feedback presenting devices of a presenting timing of a haptic feedback. As a result, the haptic feedback may be presented to each of the users depending on progress of the image and the sound.
In the past, two-way communication such as WiFi was often used as communication between apparatuses (See Patent Literature 1), and by two-way communication, a control apparatus is capable of instructing a haptic-feedback presenting device of a presenting timing of a haptic feedback.